Improvement in devices for exploding mining-powders



Patented J'u1y'24, 1877.

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PATENT PRUDENCIO (JASTELLANOS, OF SAN FRANCISCO, CALIFORNIA.

IMPROVEMENT IN DEVICES FOR EXPLODING MlNlNG-POWDERS.

Specification forming part of Letters Patent No. 193,485, dated July :4,1877 application filed January 8,- 1877.

To all whom it may concern Be it known that I, PRUDENCIO OASTELLA- Nos,of the city and county of San Francisco,

State 0 California, have invented a new and any other equivalentresistive material. This 'device is used to explode certain classesofmining-powders that are detonated by percussion, and I call itpercussive petard, a detailed description of which is as follows:

In Figure 1 is represented a vertical section of the paper or pasteboardpetard. This consists of a small rocket-cartridge, closed at the lowerextremity, and filled up to about twothirds of its capacity with apercussive powder, er, in the form of grains, and in the quantity offrom ten to sixteen grains in weight. The composition of this powderwill be given hereinafter. Said powder is retained by a top or cover ofquick-match, or of powder in paste, 0, which prevents the grains fromescaping or running out of the cartridge when it is inverted. The space0 is empty, and serves to insert in it the end of the fuse which is togive fire to the charge that is contained in the petard' when this isused. Figures 2, 3, and 4 represent vertical sections of petards of thincopper or other equivalent metal. Said petards have the form of acapsule or cartridge, Fig. 2, a vial, Fig. 3, or a matrass, Fig. 4, andare charged and stopped in the same manner asthe pasteboard petardalready described.

The percussive powder which is-contained in these petards is of myinvention, and was the object of an application for Letters Patentallowed the 8th of September, 1876; but I have found that other powders,composed principally of chlorate of potassium and a picrate, picramate,metapurpurate, &c., are percussives when they are in the form of grains,and accordingly the first-class powders invented by Messrs. Designobleand Casthelaz, and patented the 31st of March, 1868, can be used tocharge these petards. Horseley powder (a mixture of chlorate ofpotassium and galls) can also be used, (previously -granu lated;) but Ifind it of less percussive force than that of Designobles, and thelatter ought to be used.

The device described is designed to effect the explosion of themining-powders of my invention. To this elfect the petard is put incontact or is inserted in the mass of miningpowder, and it is fired bymeans of a fuse inserted in it, as has already been described. The

gases which result from the explosion of the However, the use of themetallic petards is preferable in some casesmining under water, forexample.

These petards can be used for the explosion of giant and other similarpowders, in place of the percussion-caps loaded with fulminate ofmercury,-that are generally used for this purpose, and from which occurfrequent and disastrous accidents. My petards are not dangerous, becausethe powder contained in them is less easily exploded than the fulminateof mercury, and is not compressed inside thetube. For these reasons theydo not explode intempestively by any light shock, or by compression, asthe percussion-caps. The petards explode by heat or fire, but lesseasily than the percussion caps, especially those of pasteboard.

My petards will be found very similar to other articles already known,and it is indispensable to relate here the exact distinction betweenthem.

a. The percussive petard of pasteboard differs from the fire-crackers,in that the former is loaded with a percussive powder, and the latter,on the contrary, contain common black powder, and for this reason theirexplosion makes a noise only, without striking or effecting theexplosion of the mining-powders referred to.

b. It is well known that for the explosion of nitro-glycerine largewooden or tin or pasteboard petards are used, loaded with gunpowder, inquantity of from one-third to one-fourth of an ounce. These petards,whose explosion occasions an emission of hot gases and a commotion, (notpercussion,) have been experimented with for the explosion of dynamite,and have been found unprofitable in practice, on account of their largebulk, weight, and cost, and also because their action is uncertain,occasioning frequently the combustion of the dynamite without explosion.The petards which I propose are small and light, containing a small quantity of very percussive powder in grains, and do not burn thenitroglycerine powders without exploding them.

a. A class of percussion-caps are known, equal in form to the petard,Fig. 2, loaded, as are all my petards, with a powder composed ofchlorate of potassium, picrate, &c.' The essential difference betweenboth articles consists in the condition in which the charge is placed ineach one of them. My petards, containing said powder in grains, make avery percussive explosion by contact with the fire of the fuse, butcannot be used as percussioncaps for fulminating-arms or artillery,because they do not detonate by an ordinary shock. The aforesaidpercussion-caps are, to the contrary, very fulminating by shock, becausethe powder contained in them is heavily compressed in the tube, and forthis reason they do not produce a percussive explosion when they areignited by means of a fuse, and I have found that they are useless forthe explosion of nitr'o-glycerine powders, which they only igniteWithout exploding them.

d. The petards of pasteboard, Fig. 1, and those of copper, Figs. 2 and3, have the same form as certain cartridges for the loading offire-arms. However, neither of said petards can be applied to this use,because the powder contained in them is so powerful that its explosionwould burst the barrel, and its use would be very dangerous.

I claim as my invention The percussive petard here described, as animproved device for exploding mining-powders which fulm'inate bypercussion, the same consisting in a small cartridge or vase of paper,copper, or of other equivalent material, charged, in part, with apercussive granulated powder, composed of chlorate of potassium and apicrate, and with a top of quick-match or its equivalent, the same vasehaving an empty space to receive a fuse to fire it, constructed andadapted for use substantially as described.

- PRUDENUIO OASTELLANOS.

Witnesses:

I. DE URIOSTE,

MODESTO GARCIA.

